Technical Field
The present disclosure relates to a drive mechanism including a brushed motor.
Background
A technique using a brushed motor as a means of driving electrical components such as electric mirror storage devices and door lock opening/closing devices (e.g., see JP Unexamined Patent Application Publication No. 2008-167537) is known. There is also knowledge of a malfunction of a brushed motor caused by siloxane contained in fragrances or cosmetics (e.g., see JP Unexamined Patent Application Publication No. 2009-077520). This phenomenon occurs when siloxane, which is organosilicon, is decomposed by electric discharge (spark) produced between a brush of a brushed motor and a commutator into silicon oxide (SiO2), which adheres to the surface of the brush and the commutator. As is well known, silicon oxide has electrical insulating properties. Thus, a silicon oxide film formed on the surface of the brush and the commutator increases the conduction resistance between the brush and the commutator, thereby causing malfunction of the brushed motor.
A brushed motor having a completely sealed structure may be considered as a measure of suppressing the malfunction of the brushed motor due to siloxane. However, such a brushed motor having a completely sealed structure may cause problems such as increase in size, complexity of structure, increase in weight, and increase in cost, and thus is unsuitable for application to actual products.